| Abbreviation | Definition |
|---|---|
| KY | Kiloyear |
| LADAC | Louisiana Deep Austin Chalk |
| LAS | Log ASCII Standard |
| LBOD | Left Bank Outfall Drain |
| LCS | Liquid Cooling System |
| LDG | Landing |
| LDGO | Lamont Doherty Geological Observatory |
| LE | Lower Eldorado River |
| LECO | Lake Erie Coast Ohio |
| LFAS | Low Frequency Active Sonar |
| LFO | Low Frequency Oscillations |
| LG | Lower Ground |
| LGS | Louisiana Geological Survey |
| LH | Laetoli Hominid |
| LHG | Licensed Hydrogeologist |
| LHGB | Lesser Himalayan Gneissic Basement |
| LIGO | Laser Interferometer Gravitational-Wave Observatory |
| LIP | Large Igneous Province |
| LISS | Live Internet Seismic Server |
| LITE | Logic Involving Time And Evolution |